Cannot iterate through array inside array of dictionaries

Question

I'm having trouble parsing a response into workable objects in swift.

Basically, this is the response I get (simplified data for viewing purposes)

"[{\"CO2\":0,\"Places\":[{\"Name\":\"RT(Esc. Sec.)\",\"Code\":\"ST_RT\",\"Type\":0,\"CoordX\":41.176750183105469,\"CoordY\":-8.5490522384643555,\"Provider\":\"ST\",\"Lines\":null},{\"Name\":\"Esc.Sec RT\",\"Code\":\"ST_RT2\",\"Type\":0,\"CoordX\":41.175251007080078,\"CoordY\":-8.54929256439209,\"Provider\":\"ST\",\"Lines\":null},{\"Name\":\"SM\",\"Code\":\"ST_SM\",\"Type\":0,\"CoordX\":41.173740386962891,\"CoordY\":-8.5474367141723633,\"Provider\":\"ST\",\"Lines\":null}],\"Direction\":\"R\"}]"

After I receive the response I do the following:

let dict = try! JSONSerialization.jsonObject(data: responseData!, options: .allowFragments) as? [[String:Any]] ?? [[String:Any]]()

Which results in the following dictionary (I'm sorry for the picture, but I could not take a print screen. Plus those 44 elements are the total number of Places, but I've simplified the response string as I said above)

My problem is, I cannot access each Place dictionary. I've tried iterating through dict["Places"] but that does not seem to work, which I do not understand, given it is an NSArray.

I may be missing something simple, but I can't seem to figure it out.

Any help is welcome.

Thanks!

Abandon JSONSerialization and come into the real world with Codable. — matt, Jul 13 '20 at 22:14
I use codable in other instances, but I can't use it here. It throws an error saying it expected Dictionary but got an array. — kyrers, Jul 13 '20 at 22:15

score 1 · Accepted Answer · answered Jul 13 '20 at 22:18

You can try

// MARK: - Root
struct Root: Codable {
    let co2: Int
    let places: [Place]
    let direction: String

    enum CodingKeys: String, CodingKey {
        case co2 = "CO2"
        case places = "Places"
        case direction = "Direction"
    }
}

// MARK: - Place
struct Place: Codable {
    let name, code: String
    let type: Int
    let coordX, coordY: Double
    let provider: String
    let lines: String?

    enum CodingKeys: String, CodingKey {
        case name = "Name"
        case code = "Code"
        case type = "Type"
        case coordX = "CoordX"
        case coordY = "CoordY"
        case provider = "Provider"
        case lines = "Lines"
    }
}

let res = try JSONDecoder().decode([Root].self,from:data)
print(res.places)

Cannot iterate through array inside array of dictionaries

1 Answers1